Fluid-filled active damping apparatus

Abstract

A fluid-filled active damping apparatus having a pressure receiving chamber partially defined by a rubber elastic body connecting a first and second mounting member; an oscillation plate defining a part of the pressure receiving chamber, and supported in a displaceable fashion; an electromagnetic actuator disposed on one side of the oscillation plate remote from the pressure receiving chamber, with its output member connected to the oscillation plate; an equilibrium chamber partially defined by a flexible diaphragm; and an orifice passage connecting the pressure receiving chamber and equilibrium chamber. A rigid annular guide member is disposed about the oscillation plate with a slight gap therebetween, such that these members are mutually displaceable in the axial direction. The guide member is elastically supported by and connected to the second mounting member via an elastic support member.

1. A fluid-filled active damping apparatus comprising:
 a first mounting member; 
 a second mounting member; 
 a rubber elastic body elastically connecting the first and second mounting members; 
 a pressure receiving chamber filled with a non-compressible fluid, whose wall is partially defined by the rubber elastic body, and subjected to input of vibration; 
 an oscillation plate defining an another portion of the wall of the pressure receiving chamber, and supported in a displaceable fashion; 
 an electromagnetic actuator disposed on one side of the oscillation plate remote from the pressure receiving chamber, with an output member thereof connected to the oscillation plate, the oscillation plate being driven by means of current applied to the electromagnetic actuator to thereby control pressure in the pressure receiving chamber; 
 a rigid annular guide member disposed about the oscillation plate with a slight gap interposed therebetween, such that the annular guide member is displaceable in an axial direction with respect to the oscillation plate; 
 an elastic support member elastically interposed between and connected to the annular guide member and the second mounting member so that the annular guide member is elastically supported by and connected to the second mounting member via the elastic support member; 
 an equilibrium chamber filled with the non-compressible fluid, whose wall is partially defined by a flexible diaphragm to readily permit change in volume; and 
 an orifice passage for permitting a communication between the pressure receiving chamber and the equilibrium chamber, 
 wherein the rigid annular guide member is disposed coaxially about the oscillation plate, and the slight gap between the annular guide member and the oscillation plate is made small enough to prevent flow of the fluid therethrough. 
 
   
   
     2. A fluid-filled active damping apparatus according to  claim 1 , wherein the elastic support member extends with generally constant cross-sectional shape around an entire circumferential direction about a center axis of the annular guide member. 
   
   
     3. A fluid-filled active damping apparatus according to  claim 1 , wherein at least one of an outer peripheral face of the oscillation plate and an inner peripheral face of the annular guide member, which are situated in opposition to each other with the slight gap therebetween, is formed of synthetic resin material. 
   
   
     4. A fluid-filled active damping apparatus according to  claim 1 , wherein the annular guide member and the elastic support member are formed independently from each other, and a fastening mechanism is provided to affix an outer peripheral edge of the annular guide member and an inner peripheral edge of the elastic support member to each other, utilizing an elastic behavior of the elastic support member. 
   
   
     5. A fluid-filled active damping apparatus according to  claim 1 , wherein the oscillation plate is of a construction integrally having a main plate portion of disk shape, and a rim portion of tubular shape rising up in the axial direction at an outer peripheral edge of the main plate portion. 
   
   
     6. A fluid-filled active damping apparatus according to  claim 1 , wherein a natural frequency of the elastic support member is set to a frequency range higher than a tuning frequency of the orifice passage. 
   
   
     7. A fluid-filled active damping apparatus according to  claim 1 , wherein the flexible diaphragm is affixed fluid-tightly at an outer peripheral edge thereof to the second mounting member, and a connector rod connecting the output member of the electromagnetic actuator and the oscillation plate is disposed fluid-tightly passing through a center portion of the flexible diaphragm. 
   
   
     8. A fluid-filled active damping apparatus according to  claim 1 , wherein an annular fastener member is disposed to an outer peripheral side of the annular guide member and spaced apart therefrom, and wherein the annular guide member is affixed to an inner peripheral edge of the elastic support member, and the annular fastener member is affixed to an outer peripheral edge of the elastic support member so that the annular fastener member is fluid-tightly fastened to the second mounting member.